• Double membrane with an internal membrane space between the two units, the inner one infolded into the interior of the organelle as a series of cristae; sites of oxidative phosphorylation reactions that produce cellular energy in the form of ATP.
  CRISP Thesaurus
  National Institutes of Health, 2006
• Either of the lipid bilayers that surround the mitochondrion and form the mitochondrial envelope.
  Gene Ontology Dictionary
  Gene Ontology Consortium, 2021
• The double membrane structure surrounding the mitochondrion and separating it from the cell cytoplasm. The two membranes are separated by an intermembrane space. The electron transport chain resides in the inner mitochondrial membrane.
  NCI Thesaurus
  U.S. National Cancer Institute, 2021
• The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021